1. Field of the Invention
The present invention relates to a display device, and more particularly to a technique effectively applied to a liquid crystal display having a reflector type back light unit in which a light source is a fluorescent lamp.
2. Description of the Related Art
Conventionally, there is a liquid crystal display using a liquid crystal display panel as a display device such as a television or personal computer (PC: Personal Computer) display. Some liquid crystal displays have a back light unit having a light source such as a fluorescent lamp disposed behind the liquid crystal display panel.
The back light unit called a reflector type has a light source disposed in an area overlapping the display surface of the liquid crystal display panel as seen from the observer. The reflector type back light unit is easy to increase the light quantity (luminance), and mainly employed for the large liquid crystal display for use in the room such as a liquid crystal television or desk top PC display.
Also, the light source for the reflector type back light unit is generally a fluorescent lamp such as a cold cathode fluorescent lamp (CFL). In recent years, the back light unit using a light emitting diode (LED) has been proposed.
By the way, the fluorescent lamp usually emits light radially from the peripheral face. Therefore, the reflector type back light unit using the fluorescent lamp is provided with a reflecting member for guiding the light, outgoing in a direction opposite to the direction where the liquid crystal display panel resides, or a direction almost parallel to the display surface, toward the liquid crystal display panel. Conventionally, in the reflector type back light unit, the reflecting member may be, for example, a reflector in which the outer periphery of a metallic plate is bent to the liquid crystal display panel and inclined.
The reflector type back light unit for the large liquid crystal display such as a liquid crystal television using a metallic frame having a beam-like horizontal plate and a side wall to increase the resistance against bending or torsion stress has been proposed (e.g., refer to the following patent document 1).
[Patent document 1] JP-A-2002-90736